Mission complete: Progress M-26M falls into the Pacific Ocean

The Progress M-26M spacecraft was instructed to depart the International Space Station today, Aug. 14, and shortly thereafter it re-entered and burned up in Earth’s atmosphere. Photo Credit: NASA

Russia’s Progress M-26M cargo craft undocked from the Zvezda module of the International Space Station (ISS) at 6:19 a.m. EDT (10:19 GMT) today; it re-entered Earth’s atmosphere some four hours later, falling into the Pacific. The intense heat of re-entry caused the vehicle to burn up, and the remaining hard-melting elements reached the surface of the ocean, several thousand miles away from the capital of New Zealand, Wellington.

“The spacecraft’s remains have reached the surface of the ocean,” said the Russian Mission Control Centre located in Korolyov, Moscow Oblast.

The area where Progress M-26M fell is called the “Spacecraft Cemetery” as cargo ships are routinely deposited there. It has been chosen for its remoteness, so as to not pose any threat of loss or harm to humans.

Progress M-26M, built by RKK Energia, was launched to the ISS on February 17, 2015, from the Baikonur Cosmodrome in Kazakhstan. It docked with the Zvezda service module less than six hours later. Progress 58, as it has been dubbed by NASA, delivered approximately 2.37 metric tons of cargo and supplies to the station. The spacecraft was also used to boost the space station this past May.

The International Space Station is seen from the cameras of the Progress M-26M cargo craft shortly after it undocked. Photo Credit: NASA TV

After the arrival at the station, Progress’ cargo was transferred to the ISS. This includes dry cargo that is transferred by the crew, and water that is also transferred internally, oxygen and nitrogen gas that is released to re-pressurize the station’s atmosphere, and propellant which is transferred via a dedicated transfer system.

Preparations for the spacecraft’s departure were made this past week. On Friday, mission controllers in Moscow configured the Progress for free flight and the vehicle was demated from ISS electrical systems. The undocking itself went as planned when loaded springs within the docking mechanism pushed the Progress and ISS apart at a relative speed of just 0.33 ft. per second.

The spacecraft drifted away from ISS for three minutes to open up a sufficient gap for the first thruster firing – a 15-second burn of the craft’s thrusters to increase the opening rate by more than 2 feet (0.6 meters) per second, putting it on a course to leave the station’s vicinity. During its flight to Earth, the vehicle did not perform any secondary mission objectives.

The departure of the Progress M-26M vehicle clears the Zvezda docking port for the relocation of the Soyuz TMA-16M spacecraft, currently slated to take place on August 28. Expedition 44 Commander Gennady Padalka of the Russian Federal Space Agency (Roscosmos), Flight Engineers Scott Kelly of NASA and Mikhail Kornienko of Roscocmos, will move their Soyuz from the Poisk module to Zvezda during a half-hour flight around the ISS.

The relocation will enable the delivery of a new Soyuz to the station on Sept. 2, which will transport Russian commander Sergei Volkov, Andreas Mogensen (ESA), and Kazakh cosmonaut Aidyn Aimbetov to the station. The Soyuz TMA-18M will also bring Kelly and Kornienko home next March concluding their one-year mission.

During its return trip, Progress can be loaded with 1 to 1.6 tons of trash and 800 lbs. (363 kg) of liquid waste.

Progress was developed to carry propellant and cargo to the Salyut and then Mir space stations (the first Progress flew in 1978 to Salyut 6). It is now used to resupply the ISS; the next Progress spacecraft, M-29M, is slated for October 1. Progress docks automatically to the Space Station; the craft also has a backup remote control docking system. Progress is composed of three modules: Cargo, Refueling, and Instrument-Service. In addition to their main mission as cargo spacecraft, they are used to adjust the ISS’s orbit and carry out scientific experiments.

Progress has been used to service the Salyut and Mir space stations – and now, the International Space Station. Photo Credit: NASA

Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.